Electrical synchronous braking device



P R. BARTHELEMY 1,823,779

ELECTRICAL SYNCHR ONOUSBRAKING DB VIQE Filed Oct. 6, 19:50

I l nve nl'or 1am 301116181119 Patented Sept. 15, 1931 UNITED STATES PATENT OFFICE RENE nAn'rnELEnY, or FONIENAY-AUZ-BOSES, 5mm, FRANCE, AssIGNoB. 'ro cou- PAGNIE roux LA r'AnaIcA'noN mas conr'rauas arr MATERIAL n'usrmas A on, or MONTROUGE, same, FRANCE, A JOINT-STOCK conrm or FRANCE ELECTRICAL SYNCHBQNOUS BRAKING DEVICE Applicationflled October 8, 1830, Serial ll'o. 488,788, and in France April 8, 1930.

The present invention relates to a synchronous brakin device for use in controlling the speed a rotating member.

I have already proposed in an application Ser. No. 443,187 filed April 10, 1930 for Devices for synchronizing electric motors to obtain a braking action functional of the frequency of the synchronizing oscillation and I have described in this application several ways of carrying this principle into effect.

The object of the present invention is to provide another means of carryin out the principle by providing an action unctional ll of the rotation'itself of the member to be synchronized and an action controlled by the incident, voltage. A

The accompanying drawing shows a brake control according to the invention.

Reference being had to the drawing, I have shown a metallic disc D which may be the perforate disc of a television receiver and on which acts the drivin an induction motor M similar, or example, to that utilized in induction meters.

On the axle XY of the disc, is mounted a commutator C which, for the space of half a revolution, enables the grid of a valve with three or more electrodes to be polarized negatively to a suitable value and, during the other half revolution, to brin said grid to a considerably higher potentia for exam le that of the filament. This is accomplis ed by means of a battery P and a resistance R.

The plate current of the valve A will thus undergo considerable variations: in practice, it will be reduced to zero for half a revolution and will have a high value during the 40 following half revolution. The current flowing through the electromagnet E, whose flux acts on the disc, thus produces a considerable brakin action for half a revolution.

The disc ta es up a mean speed which depends on this braking action the latter being interrupted at each revo ution, and on the torque supplied by the coils M genera zll lly fed flrlom the mairlis. 8 ed e sync roni vo tage is appli through the medil l in of the transformer T torque of amplifying valve, for exerting) which is connected to the grid of the valve (ordtg another grid if the valve has several g It will be understood that the effect of the synchronizing voltage is to modify the brakin action exerted by the electromagnet E on t e disc and that it is possible to ob tain beat effects which will regulate the speed and rotational phase of the disc as a function of the incidental synchronizing voltage, provided that the speed at which the disc rotates when the synchronizing voltage is not applied differs but slightly from the speed of synchronism.

I claim:

1. In a synchronous device, the combination of a rotatable disc, electromagnetic means for exerting a driving torque on said disc, a source of alternating current for synchronizing said disc, an amplifying valve including a grid on which the synchronizing voltage is applied, electroma etic means mounted in the plate circuit 0 said amplifying valve for exerting a braking torque on said disc, a biasing-battery, and means controlled by the rotation of said disc for periodically connecting said biasing battery to the grid of said amplifying valve.

2. In a synchronizing device, the combination of a rotatable disc, electromagnetic means for exerting a driving torque on said disc, a source 0 alternating current for synchronizing said disc, an amplifying valve including a grid on which the synchronizing voltage is applied, electroma etic means mounted in the plate circuit 0 said a brakin torque on said (1150, a biasin atter an a commutator rotated by sai disc or periodically connecting said biasing battery to the grid of said am lifying valve.

RE BARTHELEMY' 

